1. Technical Field
The present invention relates to a seal and, in particular, to a seal for use in a hydraulic apparatus, such as an integral power steering gear.
2. Description of the Prior Art
A known integral power steering gear includes a housing containing fluid under pressure. A side cover closes an opening in the housing. A seal is disposed between and seals between the side cover and the housing. The seal is made from rubber that is molded on a metal stamping.
The present invention is a seal for use in a hydraulic apparatus, the hydraulic apparatus having first and second parts that are fastened to each other and that have facing major side surfaces that include aligned fluid pressurized openings. The seal seals between the major side surfaces of the first and second parts. The seal has generally planar inner and outer major side surfaces and a seal opening extending therebetween that is aligned with the openings in the first and second parts when the second part is secured to the first part with the seal clamped between them. The seal has an annular edge portion extending around and defining the opening in the seal. The edge portion has a free condition in which annular lip portions of the seal edge portion project from the planes of the inner and outer major side surfaces of the seal. The seal edge portion has a clamped condition when clamped between the first and second parts in which the lip portions are disposed between the planes of the inner and outer major side surfaces of the seal. The lip portions when in the clamped condition define an annular groove extending around the edge portion. The groove receives fluid pressure to act on the lip portions to urge the lip portions into sealing engagement with the first part and with the second part.